topic Re: Aironet 2800 duplex mismatch on WLC 5520 with 8.5.160 and C2960X with 15.2(7)E0a in Wireless

Aironet 2800 duplex mismatch on WLC 5520 with 8.5.160 and C2960X with 15.2(7)E0a

messe2004 — Mon, 05 Jul 2021 18:43:35 GMT

I had running 40 Pieces of Aironet 2802I on a WLC 5520 with 8.5.160 temporary for an event.

I had on one port of an 2960X with SW 15.2(7)E0a the following issue:

%CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on GigabitEthernet1/0/8 (not half duplex), with AP_RES_101_2802I GigabitEthernet0 (half duplex).

The AP´s were deployed to six 2960X but the issue was on only one port of an 2960X although all switchports and all AP´s had the same identical configuration.

Re: Aironet 2800 duplex mismatch on WLC 5520 with 8.5.160 and C2960X with 15.2(7)E0a

Leo Laohoo — Mon, 17 Feb 2020 10:56:10 GMT

@messe2004 wrote:

I had on one port of an 2960X with SW 15.2(7)E0a

First, try upgrading the firmware. DO NOT use 15.2(7)E0a. Use a different version.

Re: Aironet 2800 duplex mismatch on WLC 5520 with 8.5.160 and C2960X with 15.2(7)E0a

messe2004 — Mon, 17 Feb 2020 11:03:00 GMT

But 15.2.7E0a is the Cisco suggested version:

https://software.cisco.com/download/home/284795740/type/280805680/release/15.2.7E0a

Which should i use instead?

Re: Aironet 2800 duplex mismatch on WLC 5520 with 8.5.160 and C2960X with 15.2(7)E0a

Scott Fella — Mon, 17 Feb 2020 12:25:05 GMT

Did you verify the cable run to the ap? If you swapped the ap to a known good one, did you see the same results?

Re: Aironet 2800 duplex mismatch on WLC 5520 with 8.5.160 and C2960X with 15.2(7)E0a

messe2004 — Mon, 17 Feb 2020 12:36:06 GMT

No i did´nt, but the switchport was running on 1000Full with no errors and i had no traffic impact. Only the error message was in the log. And with sh cdp neighbors detail i saw the same error. I cannot reproduce or test anymore, it was for an event last week, the event is finished in the meantime and the AP´s are not active anymore.

I can test it at the next event, if it will appear again.

Re: Aironet 2800 duplex mismatch on WLC 5520 with 8.5.160 and C2960X with 15.2(7)E0a

Scott Fella — Mon, 17 Feb 2020 14:35:05 GMT

Seems to me that it’s a cabling issue, but until you perform some process of elimination, it’s all a guess.

Re: Aironet 2800 duplex mismatch on WLC 5520 with 8.5.160 and C2960X with 15.2(7)E0a

messe2004 — Mon, 17 Feb 2020 15:23:35 GMT

Ok, i cannot do anymore right know, if ist will appears in the future i will try some elimination processes.

Re: Aironet 2800 duplex mismatch on WLC 5520 with 8.5.160 and C2960X with 15.2(7)E0a

Leo Laohoo — Mon, 17 Feb 2020 21:08:31 GMT

@messe2004 wrote:

Which should i use instead?

15.2(7)E1